Medicaid is the United States health program for people with low incomes and resources. It is a means-tested program, jointly funded by the state and federal governments, and is managed by each state. People served by Medicaid must be U.S. residents or legal permanent residents and include low-income adults, their children, and those with disabilities. Medicaid is the largest source of funding for medical and health-related services for those with limited income in the U.S.

Medicaid was created by the Social Security Amendments of 1965. Each state administers its own Medicaid program, while the federal Centers for Medicare and Medicaid Services (CMS) monitors the state-run programs and establishes requirements for service delivery, quality, funding, and eligibility standards. According to CMS, the Medicaid program provided healthcare services to more than 46 million people in 2011.